AB1183 NEUROPATHIC PAIN IN PRIMARY KNEE OSTEOARTHRITIS
Authors: A. Mougui, S. Belouaham, I. El Bouchti
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Pain is a major symptom in primary knee osteoarthritis. The mechanisms of this pain are heterogeneous explaining the variable response to different treatments. The presence of a neuropathic pain (NP) may be associated with a different phenotype disease. <h3>Objectives</h3> The present study was conducted to identify the frequency of NP in patients with painful primary knee osteoarthritis, and to investigate its correlation with socio-demographic factors, anthropometric and postural features, physical function, quality of life, and disease severity. <h3>Methods</h3> The study included 200 patients with primary osteoarthritis of the knee who did not have co-morbid disorders and/or were taking drugs that may cause neuropathy. NP was assessed by both Douleur Neuropathique 4 questions (DN4) and painDETECT questionnaires. <h3>Results</h3> The mean age of the patients was 59.15 7.62 years. The majority were women (87.5%). The mean of the body mass index was 24,72±4, 84 kg/m<sup>2</sup>. The mean of the quadriceps perimeter was 48,28±4,14cm. The mean of the waist circumference was 93,04±11,43 cm. The mean of the total Womac score was 53,61±4,93. NP was detected in 55.5% of patients according to DN4 questionnaire and in 46% according to painDETECT questionnaire. DN4 score was positively correlated with VAS (VAS Visual analogue Scale)-pain at rest (r<sub>s</sub>=0,188; P=0,009), VAS pain on movement (rs=0.173; P=0.0017), Womac pain score (rs=0.157; p=0.030), Womac stiffness score (rs=0.253; p=0.000), Physical function Womac score (rs=0.271; p=0.000), total Womac score (rs=0.305; p=0.000) and Lequesne index (rs=0.221; p=0.002), and it was negatively correlated with perimeter quadriceps (rs=-.210;p=0.008), while painDETECT score was positively correlated with VAS pain on movement (rs=0.220; p=0.002), Womac stiffness score (rs=0.147; p=0.043), Womac physical function score (rs=0.172; p=0.017), and total Womac score (rs=0.182; p=0.012). The risk factors of NP retained according to DN4 score were longer symptom duration (p=0,030) and a reduced quadriceps perimeter, whereas painDETECT score was associated with high VAS pain on movement (p=0.022). <h3>Conclusion</h3> NP is common in primary knee osteoarthritis. The presence of NP is associated with more painful pathology and extreme disability. <h3>References</h3> [1]Dimitroulas T, Duarte RV, Behura A, Kitas GD, Raphael JH. Neuropathic pain in osteoarthritis: a review of pathophysiological mechanisms and implications for treatment. Semin Arthritis Rheum. 2014;44(2):145-54. [2]Kamel SR, Ibrahim RS, Moens HM, Mohammed RM. Neuropathic pain in primary knee osteoarthritis patients: correlation with physical function, quality of life, disease severity, and serum beta nerve growth factor levels. Egyptian Rheumatology and Rehabilitation. 2021;48(1):1-9. [3]Fernandes GS, Valdes AM, Walsh DA, Zhang W, Doherty M. Neuropathic-like knee pain and associated risk factors: a cross-sectional study in a UK community sample. Arthritis Res Ther. 2018;20(1):215. [4]Güngör Demir U, Demir AN, Toraman NF. Neuropathic pain in knee osteoarthritis. Adv Rheumatol. 2021;61(1):67. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.